[jonrhy05]

over the weekend, i changed out my water pump to a high flow pump and added a 180* thermostat. Now, car barely warms up and heat/defrost never gets hot. it was a PITA last night to drive home in the rain with no window defrost. Roughly 15 minutes of drivin, should of been plenty of time to warm up.

The crappy stock gauge barely moved (maybe 1st line past 130)

[BULLET20XD]

If you put a 180 in the car you need to change it out, the stock thermostat is 192 not 180. 180 will get hot and you can use the heat/defrost but the efi requires 192. If im wrong someone will correct me. Where did you buy the thermostat? If you went to Autozone, there was your first screw up. Go to Oreillys and get a quality Murray brand and be done with it. Autozone is notourious for bad reconditioned parts,atleast my experience and 7 thermostats later i give up. Went to Oreillys and bought one and fixed it.

[hotmustang95]

It wouldn't matter if he used a 180 or a 280 t-stat in the car. If the water doesn't reach the required temps for the t-stat to open then it wouldn't make a difference. I don't know where you live. Is it cool or cold there? I know the foxes have a clutch fan that still spins even when the car is cold so it would make it more difficult for it to warm up. I remember when I had my fox and replaced all that was associated with the cooling system when I first bought it and it ran cool (180 and under) all the time. I'm thinking you just need to give the car more time now to warm up. I'd leave the 180 in there for those hot days. Not worth the time and little money to again change it out to the 192.

[DigitalDC89]

180* t-stat is fine for an efi mustang, 160* is the one you shouldn't run. I've been running one for months and never had an issue, from AutoZone as well. its possible that its stuck open, or installed the wrong way.

[jonrhy05]

install with spring towards motor?

[jonrhy05]

and i drove roughly 8 miles...figured that should be plenty to warm up

[nolife]

8 mile is more than enough to warm up. I think there is something wrong with your thermostat, it is either failed open or leaking by, on backwards (which normally causes the car to overheat though), or it slipped out of that small thin groove when you were installing it and water is going right by it? I've had bad luck with the really cheap thermostats, I buy the middle grade ones for a few more bucks.

[EscortSportage]

Im running a 180 in mine a cool night she runs 180 degress hot summer days 204. U might have put a 160 in there...

[jonrhy05]

im gonna be takin the thermostat out later today...it slipping out of the groove is probably the cause...it wasnt really wanting to go in and stay in when i had it out

[Stdyhand]

I use a 180 stat I got from Napa and it works fine. I used it since we get some really hot, humid days here.

You don't want to use one too low but 180 has always worked fine for me. With winter right around the corner though I may switch it back to 190.

[nolife]

Originally Posted by jonrhy05 im gonna be takin the thermostat out later today...it slipping out of the groove is probably the cause...it wasnt really wanting to go in and stay in when i had it out

You can get a gasket that has a sticky backing or some type of gasket sealer to hold it in place until you get the bolts on. Both work great.

[hotmustang95]

In the winter when I do use a T-stat what I do is put down a tiny bead of silicon around the edge where the T-stat goes and let it dry for 1/2 hour. Makes it real easy to install not having to worry about it sliding or falling off.

[sonataking05]

if the car was over heating then I would blame the t-stat. If his car isnt getting up to temp that is an odd issue, mustangs run a little hot in the first place so not getting up to heat is messed up. Do you have the stock radiator, and fan set up?

[jonrhy05]

well...got it fixed. between a high flow water pump and a colder thermostat...and realizing my dual fans were staying on constantly...i turned off fans and car heated up fine. fixed fans, now car warms up fine, i think. however, thinkin the defrost is a heater core issue